[css-grid] Inline issue we don't know how to solve yet.

Author: fantasai

css-grid/Overview.bs

@@ -3541,6 +3541,8 @@ Grid Sizing Algorithm</h3>
 
 			Issue: Is one cycle enough?
 
+			Issue: Would it help to have <a href="https://lists.w3.org/Archives/Public/www-style/2016Jan/0128.html">smarter heuristics</a> for the initial size calculation?
+
 		<li>
 			Finally, the <a>grid container</a> is sized
 			using the resulting size of the <a>grid</a> as its content size,